Machine gun



E. A. L. BOURDELLES.

MACHINE GUN.

APPLICATION FILED JULY 30, I917.

402 5 4 Patented Jan. 3, 1922.

3'SHEETS-SHEET I.

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Inventor.

E. A. L. BOURDELLES. MACHINE GUN.

APPLICATION FILED JULY 30.1917- 1,4 02,564. Patented Jan. 3,1922.

3 SHEETSSHEET 2- Invnta E. A. L. BOURDELLES.

MACHINE GUN.

APPLICATION FILED JULY 30,1917.

1, 10,564, Patented 3, 1922 3 SHEETS-SHEET 3- EMILE manner: LOUIS BOURDELLES, or sr-nmns, FRANCE, assrenon, o

socm'rn ANONYME DES ETABLISSEMENTS DELA'UNAY BmLEvILLE, o

ST.-DECNIS, FRANCE, A CORPORATION OF FRANCE.

MACHINE GUN.

Specification of Letters I'atent.

Patented J an. 3, 19 22.

(GRANTED UNDER THE FROVISIONS OF THE ACT OF MARCH 3, 1921, 41 STAT. L, 1313.)

To all whom it may concern:

Be it known that I, EMILE ALEXANDER LOUIS BOURDELLES, engineer, of 1 Rue de IErmitage, at St.-Denis, De artment of the Seine, France, citizen of t e French Republic, have invented certain new and useful Im rovements in or Relating to Machine Guns for which I have obtained a patent in France, No. 502,636, on application filed November 26,1912); and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to an improved machine gun of the type in which a portion of the gases produced by the explosion of the powder operates alone the whole series of automatic operations required or part of the said operations when firing at the will of the operator. Part of the gases pass by a vent in the usual way and acts ona piston which drives back what we call the operating fork. At the back end of the said fork is fixed, parallel to it and in the axis 0 the gun, a special screw, the end of which forms the striking pin. The said screw has a long pitch and works inside the breech block which acts as a nut. When the breech block can recoil, after firing the first thing done is the extraction of the cartridge case and second, after a certain travel, the ejection of it. Later on, a rotary motion is imparted to the breech block the effect of which is to move the entire feeding belt mechanism. 1

Having reached the end of its backward stroke the breech block, pushed by a spring returns to its original position taking along with it the new cartridge fed and pushing it into the barrel of the gun. When the breech is locked the striking pin, if allowed to do so, still moves.

I will describe, with reference to the accompanying drawing, a construction in accordance with this invention, but I do not limit myself tothe precise construction described and illustrated. A I

Figure 1 shows a section of the breech mechanism.-

Figure 2 is a plan of a complete machine tgun, in accordance with the present invenion.

Figure 3 is a sectional view of the belt actuat ng mechanism on line 3-3, Fig. 2.

Figure 4 ShOWs a plan of the belt feed mechanism, parts being shown in section.

drum for the cartridge belt.

Figure 1 is a perspective view of the ring actuating the feed mechanism and carrymg the e ector finger (not shown).

Figure 11 is a perspective view of part of;

the breech block front end.

Figure 12 is a front view of the back stop ring.

Figure 13 is a section of same.

F gures 14, 15, 16 are three views'illustratmg three phases of the feeding mech anism.

Referring to the drawings, 1 represents the breech casing, 2 is the breech block, 3 is the extractor, 4 the place occupied by the e e ctor, 5 the ring actuating the feed mechan1sm, 6the screw and striking pin, 7 the operatlng fork and 8 the piston which is actuated by a portion of the gases in the usuaL way, 9 is the regenerating spring, 10 the back stop ring and 11 the breech extens1on piece, 12 is the rod that connects the operating fork 7 to the driving piston 8, 13 is a roller forguiding and supporting the operating fork. These various parts are more particularly seen in Figure 1.

Figure 2 shows the following parts, viz: the breech casing 1, a lock 14, the nuts of the butt bolts 15, the firing lever 16, 17 the butt pushes, one for each hand, 18 the firing index, 19 the cylinder lock nut and 20 the gas cylinder. 21 are the radiating ribs, 22 the barrel and 23 a clamping ring. .24 is the feed passage, 25 the gun-carriage trun nions, 26 the operating rod of the pushes, 27 the receiver for the cartridge belt, 28 the cover for the belt-feeding mechanism, and 29 the operating lever, 30 are the butt handles and 31 the pivot of the belt drum '45 movement of recoil continues the breech with its two hooks. 32 is the drum, 33v the catch, 34 the brake ring and 39 a support.

Member 14, see Fig. 2, is simply a marking device for securin the cover, 28, when said cover is closed. This cover, 28, fits on top of the casing enclosing the belt actuat-' ing mechanism, and is adapted to be opened when a belt hasto be replaced or removed. The lever, or handle, 29,- is substantially a ke by which the catches, to be hereinafter re erred to, are liberated when of belt takes place, see Fig. 6.

The. other detail figures show theadglitional parts to which reference will be made in the course of the explanation of the working of the weapon, amongst others being: the feed-slide 40, the admission catch 41, the safety catch 42, the retaining catch 43, the cover 44 of the firing mechanism, a tumbler 45 provided with a hole into which there passes the crank-pin of a lever that causes the release of the firing pin. The other scribed.

In a known breech chamber 1 the breech block carries at its extreme end a locking tenon 46and an extractor 3, this extractor nearly at the end of the recoil faces in 4' the ejector device. The breech block carries, also two other tenons 46" (Fi 11) placed radially and a little behind t e tenon, 46; it is throughtheaction of these tenons, acting I as stops that the rotation of the breec block takes place as shall be seen hereafter. This breech block .2 is connected through the medium of a screw 6, the end-of which formsthe striking pin, to the operating fork 7 actuated by a gas piston 8 of known form.

The breech block 2, when it recoils after being rotated by the screw 6 connected to the fork 7, first of all disengages the three tenons 46, 46" provided on the breech block.

' The cartridge case is carried along by the in the feeding ring5, Fig. 10, when it I the feeding ring 5, two more grooves areextractor 3 and subsequently ejected downwards through the breech chamber. As the block is displaced angularly on the screw 6. This rotation of the breech block carries with it the feed ring 5 (Figures 1 and 10.).

This rotation of the breech block is produced as follows: when it recoils its locking tenon 46 (Fig. 11) engages into the limited groove 46 shown in dotted line, existin reaches the bottom of said groove rotation of coursefollows. As is plainly shown in cut 46" "on the whole length, they act as guide ways to the two longitudinal tenons 4646 placed radially at the back of thebreech block (Fig. 11).. During the recoil, these tenons pass right through the feeding ring-5 and the stop ring 10 placed directly at the back of feeding ring 5 and in which two grooves a-a are equally cut a change parts will be hereinafter deposition shown in Fi ure 3.

ing ring 5. This stop ring 10 cannot turn around so that when rotation of ring 5 takes place the two radial tenons of-the breech block are no more opposite the grooves and when the return stroke begins the resistance of stop ring 10 to the motion of the tenons produces a rotation backward of the feeding ring till the tenonscan pass right through again. Stop ring 10 besides as can be seen on Figs. 12, 13, .can retard the motion of the breech block towards the end of its forward stroke a tenon 52 at the extreme end of the breech block sliding on an incline inside the stop ring. I may add that the feeding ring 5 carries besides the cam 47 a finger, not shown, which is the ejector proper. The rotation of ring 5, in both directions, being understood I must add that the cam 47 'fixed to it can move the slide 40 an amount sufficient to displace the feeding belt one notch; the catch 41 is the piece acting on the belt. The safety catch 42 which keeps the feeding belt in its place has been previously disengaged by the action of the tenon 49, which is virtually integral with the slide 40. This tenon presses on the inclined face of a lever 50, which is capable of oscillating about the common axis 51 of the two catches. The catch 43 is disen aged by the mere thrust of the belt itself Springs are provided which tend always to keep the catches engaged. The breech block at the extreme end of its recoil begins its forward stroke pushed by the spring 9. .In the initial part of its return stroke it is caused to rotate as we have seen in'order to bring the feeding ring 5 back into the dischar ng or firing displaces the bell t rough the necessary distance so as to cause. a cartridge .to take up a position in front of the chamber. The belt having thus-been brought into osition for the insertion of a new cartri ge into alignment with the barrel, becomes automatically locked again by the catches 42 and 43 which are pushed bythe respective sprin s. The fork 7 continues-to advance and t en carries along the movable head, which pushes before it by its upper tenon 46, the cartridge which it disengages from the belt. p

In order to follow easily the working of the feeding device, I give the three Figures 14, 15, 16 illustrating three phases .of the motion of the feeding belt and showing the his movement The series of movements are reproduced in the same order until the supply of cartrid es on the belt is exhausted.

The above description relates to the use of the weapon as a continuous firing gun.

The weapon may be used also for controlled or firing at will. For this purpose, the mechanism illustrated in Figure 7 comes into play. The gunner, in this case, must make use of the butt ushes 17, either right or left Fi ures 2 and 7 which operate the firing mec anism at will. The locking of the fork 7 is produced by a sear 54 abutting against a stop 53 cut in the said fork Figure 1. This sear, 54, is rigidly connected to a platen, 55, carrying a pin 55',

assing though an oval eye out in the short ever, 45, which is part of the firing lever, 16. \Vhen the firing lever, 16, is pushed by one of the rods, 17, through the pin and slot connection, 16, the pin, 55', is acted upon and the sear, 54, is thereby lowered, and the fork, 7, is released, see Fig. 1. As the firing lever continues to move, the escapement, 56-57-58, comes into play, and by reason of the retaining cam, 57', the pawl 57, is disengaged and the spring, 59, then being under compression, as soon as the pressure is released from the pushrod, 17 moves up the pin, 55', and with it the sear, 53. When the shot has been fired it will be necessary again to push one of the rods 17 right home in order that the firing lever 16 may again disengage the sear and then bring it back to its place. That is firing at the will of the gunner. In order to pass to continuous firing all that is nec-. essary is to place the firing index 18, which is carried by the cover 44 of the mechanism, in the position shown in Figure 8. In this case a plane out in the support of the index acts as a stop limiting the rotation of the firing lever 16 in such a way -that the escapement does not work and the spring 59 cannot raise the short lever 45. The sear 54 thus remaining inoperative the operating fork 7 is no longer arrested at 54 and the firing continues automatically.

The drum upon which the charging belt is wound presents the following peculiarities.

The drum is supported by the bracket 39, upon which it is carried by a tube 60 in which a set of springs 61-62 drives a block 63, which terminates in the form of a cone and tends to keep apart the two rear branches of a double catch 6465 somewhat of the form of scissors capable of oscillating about the pivot 66.

In order to disengage the drum, all that is required is to raise the branch 64 and to bring the drum forward. A new drum provided with its band is put in position, and threaded on to the two catches, which are brought near together and which look it automatically. An adjustable cone 34 is keyed on to the tube 60 upon which the drum revolves, in such a way as to act as a brake.

The feed is effected by means of charging belts of 130 cartridges which are entirely of metal and very flexible. These belts are formed of steel bands 48 (Figure 4) indented at suitable intervals and in which claws, of a single piece, fixed very rigidly and without any riveting, are secured.

I claim:

1. In a machine gun, a breech bolt having supporting tenons, a breech stop tenon, a ring-like member having a rotary motion, and a-cartridge feeding mechanism including a slide for moving the cartridge belt, the slide being actuated by the rotary motion of said ring like member.

. 2. In a machine gun, a rotary breech bolt having supporting tenons at one end and a projection at the other end, said bolt inclosing a screw carried by the recoil mechanism and adapted to be rotated thereby, means for engaging the projection to retard the return movement of the breech bolt and a cartridge feed mechanism operable to feed a cartridge under the influence of the rotary motion of the breech bolt.

3. In a machine gun, a hollow breech bolt the rear end of which is adapted to inclose a screw carried by the recoil mechanism, forward end supporting tenons and a breech stop tenon carried by said bolt, a stop r ng for engaging said stop tenon, a ring like member surrounding said bolt and adapted to be rotated thereby, and a cartridge feed mechanism including a slide for moving the cartridge belt, the slide being actuated by the rotary motion of said ring like member.

In testimony whereof I aflix my signature, in presence of two witnesses.

EMILE ALEXANDRE LOUIS BOURDELLES.

\Vitnesses:

CHAS. I. PRESSLY, ALEXANDRE BERTHOLET. 

